The present invention relates to methods for manufacturing shoes and the shoes formed thereby and, more particularly, relates to the manufacture of clog-type shoes having soles of a foamed polymeric material as opposed to conventional wood soles.
Clog-type shoes for both women and men have enjoyed rapidly increasing polularity over the last several years. These shoes generally have included a carved wooden sole, the upper surface of which is adapted to receive and generally conform to the contours of the foot of the wearer. The sole is usually contoured in a form which includes relatively large heel and ball portions. Attached to the front portion of the sole is a flexible vamp which confines the front end portion of the foot of a wearer. In some styles, the vamp comprises a wide band of flexible material such as leather which provides an open-toed style of clog. Alternatively, the vamp may enclose the entire front portion of the clog.
The general practice in constructing such shoes is to attach the vamp to the wooden sole by overlapping the side edge portions of the vamp onto the sole and there affixing the vamp to the sole by such means as nails, tacks, staples and the like. Because the sole is wood, usually a hardwood, these conventional means for affixing the vamp to the sole are generally satisfactory and long-lasting.
As stated above, clogs have customarily been formed with wooden soles. Regardless of the care which is taken during the manufacturing process, no wooden sole can be formed that conforms precisely to the feet of all wearers as feet tend to differ slightly in their shape and proportions. Therefore, with the rigid base offered by the wooden sole, such clogs have not been comfortable for all individuals to wear. Furthermore, regardless of the degree of fit, standing or walking on such a hard surface for an extended period can and often is tiring and uncomfortable. Several approaches have been attempted to alleviate this problem. Cushioned inserts have been inserted in or affixed to the top of the sole at the heel and ball of the foot. Such techniques allow for retention of the appearance of natural woods, which appearance is believed to be partially responsible for the rise in popularity of this style.
A second proposal is to adapt more conventional modern shoe construction techniques to clog manufacture to bring greater comfort and adaptability to variances in foot configuration to the clog. Due to the mass of the clog sole, many conventional shoe constructions clearly are not acceptable. Moreover, with most, the appearance would be altered markedly or an expensive outer layer for producing that appearance would have to be added.
One recently developed shoe construction, the foamed polymeric sole, allows for the production of an outer surface on the sole that closely resembles the wood of the more conventional clog, yet would afford considerably greater comfort to the wearer. However, if it is desired to manufacture clog-type shoes which utilize such foamed polymeric materials instead of wood for the sole of the shoe to attain greater comfort, a critical problem arises in that all conventional means such as nails for attaching the vamp to the sole will be insufficient since, among other things, nails and the like will tend to be pulled from the foamed poylmeric sole upon use of the shoe. This tendency arises from two facts: (1) clogs by their nature have no strap or other means at the heel portion to draw the shoe against the foot thereby placing a great strain on the vamp, particularly at its rear edge; and (2) due to the resilience of the foamed polymeric material, there is little retentive force exerted on a mechanical fastener.
The soles of synthetic foamed polymeric material conventionally comprise a rigid member about which the foamed polymeric material is formed in molds to the desired shape of the sole. Suitable foamed polymeric materials include foamed urethanes. The appearance of the sole is attained by the dyes in the polymerics and the surface of the mold.